Sewing machine



c. w. MUELLER Feb. 3, 1931.

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BY ATTORNEY Patented Feb. 3, 1931 UNITED STATES PATENT OFFICE V CHARLES W. MUELLER, OF ST. LOUIS, MISSOURI, 'ASSIGIVOR TO LEWIS INVISIBLE STITCH MACHINE COMPANY, OF ST. LOUIS, MISSOURI, A CORPORATION OF MAINE SEWING MACHINE- .Application filed November This invention relates to new and useful improvements in sewing machines generally, although more particularly to a blmd StltCll' sewing machine for forming and retaining creases in trousers.

' Among the several objects of my invention are to provide a sewing machine with a stich forming mechanism and a work presenting mechanism whereby a trouser leg, either in its completed tubular condition or in its flat condition prior to either or both of the leg seams being formed, may be fed through the machine and a line of blind stitches formed in the inner face thereof and functioning to provide and retain a crease in said trousers, and to provide a seam for such purpose which is elastic so as to permit of the fabric giving when placed under strain such as occurs when the wearer occupies a sitting position.

With these and other objects in view which will more fully appear, the nature of the invention will be more clearly understood by following the description, the appended claims, and the several views illustrated in the accompanying drawings.

In the accompanying drawings which illustrate one form of my invention:

Figure 1 is a front elevation of a blind stitch sewing machine. embodying my invention,

Figure 2 is a left hand end elevation thereof, the end cap being removed to better disclose the work presenting mechanism, I

Figure 3 is an enlarged top plan view of the work presenting mechanism, the view being taken directly above the presser foot and showing the needle in cooperative position at the beginning of its penetrating movement,

Figure 4 is an enlarged sectional view taken on the line 4- 4 of Figure 3,

Figure 5 is an enlarged transverse sectional view taken on the line 5-5. of Figure 3, the

' view showing the fabric in operating position and the plunger at the lower end of its stroke,

Figure 6 is a view similar to Figure 5 but showing the plunger at the upper end of its stroke and the needle in position in the fabric,

7, 1928. Serial No. 317,726.

Figure 7 is a perspective view of the upper end of the plunger,

Figure.8 is a front view of a pair of trousers embodying my invention,

Figure 9 is an enlarged transverse section of one of the trouser legs showi'n in a diagrammatic manner the location 0 the crease or fold retaining means, and I Figure 10 is an enlarged detailed view looking at the inner face of the fabric and showing the line of stitches which connects the inner face of the fabric on opposite sides of the fold.

Like reference numerals designate corre sponding parts throughout the several figures of the drawings.

The present invention is illustrated herein as embodied in a blind stitch sewing machine of the well known Lewis type, and includes a base or bed plate 5, a post or standard 6-and an overhanging arm 7 which supports at its outer end a stitching head 8. Projecting laterally from the standard 6 is a work arm 9 which terminates at its free end under the stitching head 8.

The machine includes a stitch forming mechanism and a work presenting mechanism which cooperate to form a line of single thread chain 'stitches and anchor said stitches in the opposite inner faces of a trouser leg on opposite sides of the seam thereof.

In order to understand the operating parts of this machine and the function, it is advisable to first describe the trousers and the crease seam which is produced by this machine and the method of producing such seam. Therefore, referringv particularly to Figures 8,9 and 10, A designates a bifurcated garment, such as a pair of trousers, and includes leg portions aa, each including a front portion 10 and a back portion 11 which are connected by an inside leg seam 12 and an outside leg seam 13. Each leg portion a is provided with longitudinally extending front and rear folds or creases l4.14=. The trousers as thus far described are of the usual construction.

In order to retain each fold or crease 14, I have provided a means comprising a line of connected blind stitches which I have designated B and have illustrated the same diagrammaticallyin Figure 9. These stitches enter and emerge from the inner face only of the fabric and'therefore they are not exposedto the outer face thereof. ll preferably employ elastic stitches as'the same permit the fabric to give when placed under strain such as occurs when the wearer occupies a sitting position. Although several types of elastic stitches may be employed, I prefer to use what is known as a single thread chain stitch formation. Therefore the line B of stitches includes a series of connected and uniformly spaced anchored needle thread loops 6. Each loop 6 enters the inner face of the fabric and emerges from said inner face on each side of the fold 14 as indicated at 15 and 16 respectively. Each loop 6 includes two portions 17 and 18 which extend twice across the fold 14 and are disposed at an angle to each other, the portion 17 extending at right angles to the fold and the portion 18 extending at a substantial angle thereto. the degree of inclinationbeing dependent on the length of stitch, that is, the distance between points of needle penetrations. The portion 18 is the closed end of the loop and this loop is anchored by the next formed needle thread loop, as is clearly shown in Figure 10. The needle thread loops 6 enter and emerge on each side of the fold 14 along lines which are fairly close to the fold and are spaced equidistant therefrom, thus not only maintaining the-fold but also maintaining the fold in a uniform manner throughout its length. The method employed in producing this fold retaining means is disclosed in my co-pending application Serial No. 309,489, filed Got. 1, 1928, and the trousers produced by my method and by the machine forming the. subject matter of the present application is disclosed in my copending application Serial No. 290,071, filed July 3, 1928.

Rigidly attached to the lower end of the stitching head 8 is a presser foot 19 having a work receiving opening 20 formed therein. The upper face of the presser foot, on opposite sides of the opening 20, is provided with giansversely disposed needle guides 21 and A needle 23 is adapted to be reciprocate across the opening 20 and cooperate with said guides 21 and 22 during such reciprocation. This needle 23 is fixed to a needle arm 24 which is pivoted as at 25 to the stitching head 8, the pivot being disposed directly above the opening 20. The needle arm 24 is provided with a work arm 26 to which is pivotally connected as at 27 one end of a driving link 28, the other end of the link being pivotally connected as at 29 to an eccentric pin fixed to a driven gear 30 journaled on the head 8. The gear 30 is driven by a gear 31 fixed on the main driving shaft 32 which is journaled in the overhanging arm 7. Thus when the shaft invenaeo asmuch as this looper mechanism is of well known construction and is fully disclosed in my prior Patent 1,539,399, May 26, 1925, it is thought that further description thereof is unnecessary.

Cooperating with the underside of the presser foot 19 for feeding the fabric across the Work arm 9 and in a direction at right angles to the path of needle movement, I have provided a feed mechanism which includes a 4-motion feed dog 34. This feed dog is given its four motions by a feed mechanism which 1 have indicated generally by the numeral 35. This feed mechanism is of the well known type and is driven from the main rotary shaft 32 through the medium of driving connections extending through the standard 6 and work arm 9, and it is therefore thought that a detailed description thereof is unnecessary. A vertically reciprocatory plunger 36 is supported in the free end of the work arm 9 in the usual manner, and means are provided for reciprocating this plunger in timed relation to the feed dog movements and to the needle reciprocations, in a manner-well unis provided with spaced upwardly extending fabric engaging-arms 3737 which form a resultant vertical slot 38 therebetween. A retaining finger 39 has its front end secured to the presser foot 19 in front of the opening 20 by means of a screw 40. This finger extends rearwardly and thence downwardly into the opening 20 and terminates in a horizontal portion 41 which is disposed below the path of needle reciprocations and directly above the lower surface of the foot 19. The extreme rear end 42 of the retaining finger 39 terminates immediately in rear of the path of needle reciprocation and in advance of and in spaced relation to the rear wall 43 of the presser foot opening 20. The retaining finger 39 is disposed centrally of the opening 20 and extends generally in the line of feed and is located in a position to enter the slot 38 in the plunger when the plunger is moved upwardly.

In the operation of my machine, the trouser leg either in its fiat condition or in its finally formed tubular condition, is positioned below the presser foot 19 and above the feed dog 34, with the needle in the beginning of its stroke or in the position shown in vFi ures 1 and 5. Upon rotation of the main sha ft 32, the plunger 36 will be'elevate'd to the posi tionshown in Figure 6, thus elevatin the fabric on opposite sides of the retaining finger 39, and forming spaced nodes n and n in the material on opposite sides of the center line of feed, and a downwardly extending centrally located node n which is retained by the retaining finger 39. While the nodes at and n are held by the plunger, the needle 23 is given its forward or penetrating movement to the position shown in Figure 6, the needle first entering the node n, then emerging therefrom, then entering the node n and then emerging therefrom. In this movement, the

needle enters and, emerges from the upper face of the fabric only and consequently the stitches ultimately produced by the stitch forming mechanism will be invisible from the lower face of the fabric which lower face is the outer face of the trousers. The plunger 36 then begins its downward movement and simultaneously the needle 23 begins its return movement. Simultaneously with the return movement of the needle the looper of the looper mechanism 33 is actuated to cooperate with the needle thread and thereby form a loop of needle thread and position the same in readiness to be entered by the needle during thenext forward movement thereof. It will be understood that after the needle has been retracted from the fabric the feed dog 34 is given its feeding stroke to feed the fabric a stitch length distance.

From the foregoing, it will be apparent that I have provided a means below the presser foot for projecting spaced nodes of fabric or material simultaneously upwardly through the opening of the foot into needle penetrating position whereby the needle will in succession enter each node and emerge therefrom; that the path of needle oscillation is in a plane transverse to the line of feed; that the nodes of material are projected upwardly on opposite sides of the center line of feed and that the upper end of the plunger is provided with upwardly extending material engaging arms which are spaced apart a distance sufiicient to receive the retaining finger and the material therearound.

It is of course to be understood that the details of structure and arrangements of parts may be variousl changed and modified without departing my invention.

I claim:

1. In a sewing machine, the combination with a presser foot having an opening, of a feeding mechanism cooperatin with said foot, a needle mechanism mcluding a rom the spirit and scope of threaded needle reciprocating above the opening of the foot, a retaining finger located within the opening of the foot and disposed below the path of needle reciprocation, and means located below the foot for projecting spaced nodes of material simultaneously upwardly through the opening of the foot on opposite sides of the finger and into needle-penetrating position whereby the needle will in succession enter eachnode and emerge therefrom. 2. In a sewing machine, the combinatio with a presser foot having an opening, of a feeding mechanism cooperating with said foot, a needle mechanism including an oscillatory threaded needle fulcrumed on a fixed pivot directly above the opening in the foot,

a retaining finger located within the opening of the foot and disposed below the path of needle reciprocation, and means located below the foot forprojecting spaced nodes of material simultaneously upwardly through the opening of the foot on opposite sides of the finger and into needle-penetrating position whereby the needle will in succession enter each node and emerge therefrom.

I 3. In 'a sewing machine, the combination with a presser foot having an opening, of a feeding mechanismcooperating with said foot, a needle mechanism including an oscillatory threaded needle fulcrumed on a fixed pivot directly above the opening in the foot, the path of needle oscillation being in a plane transverse to the line of feed, a finger fixedly secured at its front end to the foot at a point in front of the opening therein, said finger extending rearwardly and terminating at a point in spaced relation to the rear end of the presser foot opening, and means located below the foot for projecting spaced nodes of material simultaneously upwardly through the opening of the foot on opposite sides of the finger into needle-penetrating position whereby the needle will in succession enter each node and emerge therefrom.

4. In a sewing machine, the combination with a presser foot having an opening, of a feeding mechanism cooperating with said foot, a needle mechanism including a threaded needle reciprocating above the opening of the foot, a stationary retaining finger carried by the foot, and means located below the foot including a vertically reciprocatory plunger cooperating with said retaining finger for projecting spaced nodes of material simultaneously upwardly through the opening of the foot into needle-penetrating position whereby the needle will in succession enter each node and emerge therefrom.

5. In a sewing machine, the combination with a presser foot having an opening, of a feeding mechanism cooperating with said foot, a needle mechanism including an oscillatory threaded needle fulcrumed on a fixed pivot directly above the opening in the foot,

the path of needle oscillation being in a plane transverse to the line of feed, a stationary retaining finger carried by the foot, and means located below the foot including a vertically reciprocatory plunger cooperating with said retaining finger for projecting spaced nodes of material simultaneously upwardly through the opening of the foot into needle-penetrating position whereby the needle will in succession enter each node and emerge therefrom.

6. In a sewing machine, the combination with a. presser foot having an opening, of a feeding mechanism cooperating with said foot, a needle mechanism including a threaded needle reciprocating above the opening of the foot, a stationary finger extending rearwardly in the line of feed from the front end of the foot and having its rear end free and located within the opening of the foot, and means disposed below the foot and cooperating with the finger for projecting spaced modes of material upwardly through the opening in the foot on opposite sides of the finger into needle-penetrating position whereby the needle will in succession enter each node and emerge therefrom.

7. In a sewing machine, the combination with a presser foot having an opening, of a feeding mechanism cooperating with said foot, a needle mechanism including an oscillatory threaded needle fulcrumed on a fixed pivot directly above the opening in the foot, the path of needle oscillation being in a plane transverse to the line of feed, means located below the foot for projecting spaced nodes of material simultaneously upwardly through the opening of the foot on opposite sides of the central line of feed into needle-penetrating position whereby the needle will in succession enter each node and emerge therefrom, a stationary finger extending rearwardly in the line of feed from the front end of the foot and having its rear end free and located within the opening of the foot, and means disposed below the foot and cooperating with the finger for projecting spaced nodes of material upwardly through the opening in the foot on opposite sides of the finger into needle-penetrating position whereby the needle will in succession enter each node and emerge therefrom.

8. In a sewing machine, the combination with a presser foot having an opening, of a feeding mechanism coperating with said foot, a needle mechanism including a threaded needle reciprocating above the opening of the foot, a stationary finger extending rearwardly in the line of feed from the front end of' the foot and having its rear end free and located within the opening of the foot, and a vertically reciprocatory plunger cooperating with the finger for projecting spaced nodes of material upwardly through the opening in the foot on opposite sides of the finger into mraao needle-penetrating position whereby the needle will in succession enter each node and emerge therefrom.

9. In a sewing machine, the combination with a presser foot having an opening, of a feeding mechanism cooperating with said foot, a needle mechanism including a threaded needle reciprocating above the opening of the foot, and means located below the foot including a vertically reciprocatory plunger and a cooperating stationary retaining finger for projecting spaced nodes of material simultaneously upwardly through the opening of the foot into needle-penetrating position whereby the needle will in succession enter each node and emerge therefrom, the upper end of the plunger being provided with spaced upwardly extending material-engaging arms spaced apart a distance sufficient to receive the retaining finger and the material therearound.

10. In a sewing machine, the combination with a presser foot having an opening, of a feeding mechanism cooperating with said foot, a needle mechanism including a thread ed needle reciprocating above the opening of the foot, a stationary finger extending rearwardly in the line of feed from the front end of the foot and having its rear end free and located within. the opening of the foot, and means disposed below the foot including a reciprocatory plunger and cooperating with the finger for projecting spaced nodes of material upwardly through the opening in the foot on opposite sides of the finger into needlepenetrating position whereby the needle will in succession enter each node and emerge therefrom, the upper end of the plunger being provided with spaced upwardly extending material-engaging arms spaced apart a distance suficient to receive the retaining finger and the material therearound.

In testimony whereof I hereunto affix my signature.

CHARLES W. MUELLER. 

